Surgical loading units and mounting members thereof

ABSTRACT

A mounting member for a surgical stapler is fabricated from a plastic. The mounting member has a proximal end portion and a distal end portion. The proximal end portion has a pair of vertical projections configured to be coupled to a proximal body portion of a loading unit of a surgical stapler. The distal end portion includes a pair of walls extending distally from the proximal end portion. Each wall has a boss and a strut. The boss defines a transverse bore therethrough configured to be rotatably coupled to a cartridge assembly of the loading unit. The strut extends from the proximal end portion to the boss.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a Continuation Application which claims thatbenefit of and priority to U.S. patent application Ser. No. 14/503,458,filed on Oct. 1, 2014, now U.S. Pat. 9,700,316, the entire content ofwhich is incorporated herein by reference.

BACKGROUND

Technical Field

The present disclosure relates generally to instruments for surgicallyjoining and cutting tissue and, more specifically, to surgicalinstruments having curved or straight jaw members and loading units foruse therewith.

Background of Related Art

Various types of surgical instruments used to surgically join tissue areknown in the art, and are commonly used, for example, for closure oftissue or organs in transection, resection, anastomoses, for occlusionof organs in thoracic and abdominal procedures, and for mechanicallysealing tissue.

One example of such a surgical instrument is a surgical staplinginstrument, which may include an anvil assembly, a cartridge assemblyfor supporting an array of surgical staples, an approximation mechanismfor approximating the cartridge and anvil assemblies, and a firingmechanism for ejecting the surgical staples from the cartridge assembly.

When using a surgical stapling instrument, it is common for a surgeon toapproximate the anvil and cartridge assemblies. Next, the surgeon canfire the surgical stapling instrument to emplace staples in tissue.Additionally, the surgeon may use the same instrument or a separateinstrument to cut the tissue adjacent or between the row(s) of staples.

Presently, a component or components used to rotatably couple thecartridge and/or anvil assembly to a body of the surgical staplinginstrument is constructed from stainless steel using a complexmanufacturing process.

SUMMARY

In one embodiment of the present disclosure, a mounting member for asurgical stapler is provided. The mounting member includes a bodyfabricated from a plastic and defines a longitudinal axis. The bodyincludes a proximal end portion and a distal end portion. The proximalend portion has a pair of vertical projections configured to be coupledto a proximal body portion of a loading unit of a surgical stapler. Thedistal end portion includes a pair of walls, a boss, and a strut. Thewalls extend distally from the proximal end portion. The boss is coupledto one wall of the pair of walls and defines a bore therethroughconfigured to be rotatably coupled to a cartridge assembly of a loadingunit. The strut extends from the proximal end portion to the boss.

In embodiments, the plastic may be polyetheretherketone. Thepolyetheretherketone may be carbon filled or glass filled.

In embodiments, the boss may be cylindrical and extend perpendicularlyfrom the wall of the pair of walls.

In embodiments, the body may be monolithically formed.

In embodiments, the proximal end portion of the body may further includea convex outer surface and a raised section centrally disposed on theconvex outer surface.

In embodiments, the pair of vertical projections, the pair of walls, andthe strut may have a uniform thickness equal to one other.

In embodiments, the cartridge assembly may be curved.

In another aspect of the present disclosure, a loading unit is provided.The loading unit includes a proximal body portion defining alongitudinal axis, a tool assembly, and a mounting member. The toolassembly extends distally from the proximal body portion and includes acartridge assembly and an anvil assembly fixed to a distal end of theproximal body portion. The mounting member is fabricated from a plasticand includes a body and a fastener. The body includes a proximal endportion a distal end portion. The proximal end portion has a pair ofvertical projections coupled to the distal end of the proximal bodyportion. The distal end portion includes a pair of walls, a boss, and astrut. The walls extend distally from the proximal end portion. The bossis coupled to a wall of the pair of walls and defines a boretherethrough. The strut extends from the proximal end portion to theboss. The fastener of the mounting member extends through the cartridgeassembly and the bore of the boss to rotatably couple the cartridgeassembly to the mounting member.

In embodiments, the cartridge assembly and the anvil assembly may have acurved configuration.

BRIEF DESCRIPTION OF FIGURES

Various embodiments of the presently disclosed surgical instrument aredisclosed herein with reference to the drawings, wherein:

FIG. 1A is a perspective view of a surgical stapler including a loadingunit in accordance with the present disclosure;

FIG. 1B is an enlarged view of the area of detail of FIG. 1Aillustrating the loading unit including a tool assembly and a proximalbody portion;

FIG. 2 is an exploded view of the loading unit of FIG. 1A

FIG. 3 is a perspective view, with parts separated, of a cartridgeassembly and a mounting member of the tool assembly of FIG. 1B;

FIG. 4 is a top, perspective view of the mounting member of FIG. 3; and

FIG. 5 is a bottom, perspective view of the mounting member of FIG. 3.

DETAILED DESCRIPTION

Embodiments of the presently disclosed surgical stapler including aloading unit having a proximal body portion, a tool assembly, and amounting member for rotatably coupling component(s) of the tool assemblyto the proximal body portion are described in detail with reference tothe drawings, wherein like reference numerals designate correspondingelements in each of the several views. As is common in the art, the term‘proximal” refers to that part or component closer to the user oroperator, e.g., surgeon or physician, while the term “distal” refers tothat part or component farther away from the user.

With reference to FIG. 1A, a surgical stapler of the present disclosureis indicated as reference numeral 10 having a curved tool assembly 104disposed at a distal end thereof. While not explicitly shown, thepresent application may also relate to surgical stapling instrumentshaving parallel jaw members and to electrosurgical instruments used tojoin tissue. Surgical stapler 10 includes a handle assembly 12 having amovable trigger 22, a rotating mechanism 14, an elongated or endoscopicportion 18, and a disposable loading unit (or “DLU”) 100. Endoscopicportion 18 extends distally from rotating mechanism 14. Loading unit 100is attachable to a distal end of endoscopic portion 18 of surgicalstapler 10, e.g., to allow surgical stapler 10 to have greaterversatility. Loading unit 100 may be configured for a single use and/ormay be configured to be used more than once. Examples of loading unitsfor use with a surgical stapling instrument are disclosed incommonly-owned U.S. Pat. No. 8,360,298 to Farascioni et al., the entirecontents of which are incorporated by reference herein.

With reference to FIGS. 1B-5, loading unit 100 includes a proximal bodyportion 102, a mounting member 200 (FIGS. 2-5), and a tool assembly 104.Proximal body portion 102 defines a longitudinal axis “X1,” and isreleasably attachable to a distal end 20 of endoscopic portion 18 (FIG.1A) of surgical stapler 10. Tool assembly 104 includes a pair of jawmembers, such as, for example, an anvil assembly 106 and a cartridgeassembly 108, as described in greater detail below. Mounting member 200couples proximal body portion 102 of loading unit 100 to cartridgeassembly 108 of tool assembly 104 such that cartridge assembly 108 ispivotable relative to anvil assembly 106.

With reference to FIGS. 3-5, mounting member 200 includes a body 202,fabricated from a plastic material, and a pair of fasteners 204 used topivotably interconnect mounting member 200 with cartridge assembly 108of tool assembly 104. Body 202 may be formed via plastic injectionmolding using various plastics, such as, for example, thermoplasticssuch as carbon filled or glass filled polyetheretherketone (PEEK),including polyaryletherketone (PAEK), polyetherketoneketone (PEKK) andpolyetherketone (PEK).

Body 202 may be fabricated from material composites, including the abovematerials, to achieve various desired characteristics such as strength,rigidity, elasticity, compliance, and durability. Body 202 may also befabricated from a heterogeneous material such as a combination of two ormore of the above-described materials. Body 202 may be monolithicallyformed, integrally connected, or include fastening elements and/orinstruments. The advantages of fabricating body 202 from one or more ofthe materials described above, for example, PEEK, are, for example, areduction in the number of complex machining operations of body 202,increased strength and stiffness with superior wear and chemicalresistant properties, and lower manufacturing cost.

With continued reference to FIGS. 3-5, body 202 of mounting member 200has a proximal end portion 206 a and a distal end portion 206 b defininga longitudinal axis “X2” therebetween, which is coaxial withlongitudinal axis “X1” of proximal body portion 102 of loading unit 100upon coupling mounting member 200 with proximal body portion 102. Body202 has a generally elongated configuration. In embodiments, body 202may be variously configured, such as, for example, rectangular, oblong,uniform, non-uniform, tapered, and/or polygonal. Body 202 has a channel208 extending along longitudinal axis “X2” from a proximal-most end ofproximal end portion 206 a to a distal-most end of distal end portion206 b splitting body 202 into two, symmetrical half-sections 210 a, 210b. Channel 208 has a depth “D” less than a height “H” of body 202 (FIG.4); however, it is contemplated that depth “D” of channel 208 and height“H” of body 202 are approximately equal. Channel 208 is configured forslidable receipt of a drive assembly 360, as described in greater detailbelow.

Proximal end portion 206 a of mounting member 200 has a pair of verticalprojections 212 a, 212 b extending upwardly from body 202. Each ofvertical projections 212 a, 212 b has a rectangular configuration and aU-shaped transverse cross section. Vertical projections 212 a, 212 b areconfigured to be coupled to proximal body portion 102 (FIG. 2) ofloading unit 100 by frictionally fitting into corresponding recesses(not shown) in a half-section 103 a of proximal body portion 102. Insome embodiments, vertical projections 212 a, 212 b may be secured tohalf-section 103 a of proximal body portion 102 via various fasteningengagements, such as, for example, adhesives, snap-fit engagement,and/or fasteners.

Proximal end portion 206 a of mounting member 200 further includes aconvex outer surface 214 and a raised section 216 centrally disposed onconvex outer surface 214. Raised section 216 strengthens proximal endportion 206 a, adds rigidity, and reduces deformation under loads tomaintain its original configuration. Channel 208 extends through body202 to convex outer surface 214, terminating adjacent raised section216. Proximal end portion 206 a has a planar portion 218 inperpendicular relation to convex outer surface 216. Planar portion 218has a planar face 220 oriented in a distal direction.

Distal end portion 206 b of mounting member 200 extends distally fromplanar face 220 of proximal end portion 206 a. Distal end portion 206 bincludes a pair of walls 222 a, 222 b in parallel relation to oneanother and spaced from one another by a width of channel 208. Each wall222 a, 222 b has a stepped configuration. Distal end portion 206 bincludes a pair of bosses 224 a, 224 b supported on a respective wall222 a, 222 b. Bosses 224 a, 224 b extend perpendicularly from arespective wall 222 a, 222 b, outwardly from one another and away fromchannel 208.

As illustrated in FIG. 3, bosses 224 a, 224 b are configured to bepositioned into a proximal end of a carrier 116 of cartridge assembly108 that receives and supports a longitudinally curved cartridge 118 ofcartridge assembly 108. Each boss 224 a, 224 b defines a bore 226 a, 226b therethrough extending perpendicular to longitudinal axis “X2” of body202 of mounting member 200. When mounting member 200 is disposed in theproximal end of carrier 116 of cartridge assembly 108, each bore 226 a,226 b is aligned with a hole 180 formed in the carrier 116 of cartridgeassembly 108 such that mounting member 200 is pivotally secured tocarrier 116 by fastener 204 of mounting member 200. In this way,cartridge assembly 108 is pivotably coupled to proximal end portion 102of loading unit 100 via mounting member 200. In embodiments, fastener204 may be variously configured, such, as, for example, a self-tappingscrew or a pivot pin. In embodiments, one fastener 204 is used to extendthrough both bosses 224 a, 224 b.

Distal end portion 206 b of body 202 of mounting member 200 includes afirst pair of struts 228 a, 228 b. Each of the first pair of struts 228a, 228 b extends from planar surface 220 of proximal end portion 206 ato a proximally-facing side of a respective boss 224 a, 224 b to resistflexion of walls 222 a, 222 b relative to planar surface 220. Each wall222 a, 222 b includes a second pair of struts 230 a, 230 b extendingfrom an upwardly facing side of a respective boss 224 a, 224 b. Struts230 a, 230 b resist flexion of bosses 224 a, 224 b relative to walls 222a, 222 b and maintains channel 208 open for drive member 360 to freelytranslate proximally and distally and minimize binding.

As shown in FIG. 4, each component of body 202, for example, verticalprojections 212 a, 212 b, walls 222 a, 222 b, bosses 224 a, 224 b, andstruts 228 a, 228 b, 230 a, 230 b, is constructed from one, continuous,monolithically formed wall having a uniform thickness throughoutprovided during manufacturing of body 202 of mounting member 200. Assuch, one piece of plastic may be used to manufacture body 202 and thenumber of steps required to manufacture body 202 is reduced.

With reference to FIGS. 1B, 2, and 3, each of anvil assembly 106 andcartridge assembly 108 is longitudinally curved. That is, anvil assembly106 and cartridge assembly 108 are curved with respect to thelongitudinal axis “X1” defined by proximal body portion 102. As usedherein with respect to curved parts of the surgical stapler 10 of thepresent disclosure, the term “distal,” which typically refers to thatpart or component of the instrument that is farther away from the user,refers to the portion of the curved part that is farthest along an axisthat follows the curve of the curved part. That is, while anintermediate portion of a curved part may be farther from the userduring use, the portion of the curved part that is farthest along itsaxis is considered “distal.”

In disclosed embodiments, the radius of curvature of both anvil assembly106 and cartridge assembly 108 is between about 1.00 inches and about2.00 inches, and in particular, may be approximately 1.40 inches. Thecurved jaw members, as compared to straight jaw members, may helpfacilitate access to lower pelvis regions, e.g., during lower anteriorresection (“LAR”). Additionally, the inclusion of curved jaw members mayallow increased visualization to a surgical site and may also allow moreroom for a surgeon to manipulate target tissue or the jaw membersthemselves with his or her hand.

One jaw member is pivotal in relation to the other. In the illustratedembodiments, cartridge assembly 108 is pivotal in relation to anvilassembly 106 and is movable between an open or unclamped position and aclosed or approximated position via mounting member 200, as describedabove. Cartridge assembly 108 is urged in the open position via abiasing member, e.g., a pair of compression springs 133 (FIG. 2)disposed between an anvil cover 110 of anvil assembly 106 and cartridge118 of cartridge assembly 108 (FIG. 2).

With reference to FIG. 2, anvil assembly 106 includes longitudinallycurved anvil cover 110 and a longitudinally curved anvil plate 112,which includes a plurality of staple forming depressions (not shown). Inembodiments, the radius of curvature of both anvil cover 110 and anvilplate 112 is between about 1.00 inches and about 2.00 inches, and inparticular, may be approximately 1.40 inches. Anvil plate 112 is securedto an underside of anvil cover 110 to define a channel (not shown)between plate 112 and cover 110. When tool assembly 104 is in theapproximated position, the staple forming depressions (not shown) arepositioned in juxtaposed alignment with cartridge assembly 108.

With continued reference to FIGS. 1B, 2, and 3, cartridge assembly 108includes a longitudinally curved channel or carrier 116 which receivesand supports longitudinally curved cartridge 118. Cartridge 118 can beattached to carrier 116 by adhesives, a snap-fit connection, or otherconnection. In embodiments, the radius of curvature of both carrier 116and cartridge 118 is between about 1.00 inches and about 2.00 inches,and in particular, may be approximately 1.40 inches. Cartridge 118includes a pair of support struts 124 which rest on sidewalls 117 ofcarrier 116 to stabilize cartridge 118 on carrier 116. Support struts124 also set the height or location of cartridge 118 with respect toanvil plate 112. An external surface of carrier 116 includes an angledcam surface 116 a.

Cartridge 118 defines a plurality of laterally spaced staple retentionslots 128, which are configured as holes in a tissue contacting surface140 of cartridge 118. Each slot 128 is configured to receive a staple130 therein. Cartridge 118 also defines a plurality of cam wedge slots(not shown), which accommodate staple pushers 132 and which are open onthe bottom (i.e., away from tissue contacting surface 140) to allow alongitudinally curved actuation sled 136 to pass therethrough.

With reference to FIG. 2, staple cartridge 118 includes a centrallongitudinally curved slot 126, and three longitudinally curved rows ofstaple retention slots 128 positioned on each side of curvedlongitudinal slot 126. In embodiments, the radius of curvature of bothslot 126 and pusher 132 is between about 1.00 inches and about 2.00inches, and in particular, may be approximately 1.40 inches. Morespecifically, actuation sled 136 passes through the cam wedge slots (notshown) defined in cartridge 118 and forces staple pushers 132 towardsrespective staples 130. Staples 130 are then forced out of theirrespective staple retention slots 128.

With continued reference to FIG. 2, proximal body portion 102 of loadingunit 100 includes an inner body 103 formed from molded half-sections 103a and 103 b, an outer body 302, a drive assembly 360, and a drivelocking assembly 310. Inner body 103 is coupled to cartridge assembly108 by mounting member 200, as described above. Inner body 103 iscoupled to anvil assembly 106, as described below. The illustratedembodiment of anvil cover 110 includes a proximally extending finger 188having a pair of cutouts 190 formed therein. Cutouts 190 are positionedon each lateral side of finger 188 to help secure anvil cover 110 tohalf-section 103 a. More particularly, half-section 103 a includes achannel 105 therein, and channel 105 includes a pair of protrusions 105a. Finger 188 of anvil cover 110 mechanically engages channel 105 ofhalf-section 103 a, such that cutouts 190 are aligned with protrusions105 a. Outer body 302 of proximal body portion 102 covers finger 188 andchannel 105. The configuration of finger 188 and channel 105 facilitatesa secure connection between anvil cover 110 and half-section 103 a.Moreover, this connection results in a non-movable (e.g., non-pivotable)engagement of anvil assembly 106 with proximal body portion 102.

Loading unit 100 includes a locking mechanism 310 including a lockingmember 320 and a locking member actuator 322. Locking member 320 isrotatably supported within a longitudinal or transverse slot 325 formedin a proximal portion of upper housing half 103 a of inner body 103 ofloading unit 100. Locking member 320 is movable from a first position,in which locking member 320 maintains drive assembly 360 in a prefiredposition, to a second position, in which drive assembly 360 is free tomove axially.

Locking member 320 includes a semi-cylindrical body 324 which isslidably positioned within transverse slot 325 formed in upper housinghalf 103 a of body portion 103. Cylindrical body 324 includes a radiallyinwardly extending cam member 328 and a radially inwardly extendingfinger 330. Finger 330 is dimensioned to be received within a notch 362formed in drive assembly 360. Engagement of finger 330 in notch 362 ofdrive assembly 360 prevents drive assembly 360 from moving linearlywithin proximal body portion 103 to prevent actuation of loading unit100 prior to attachment of loading unit 100 to endoscopic portion 18 ofsurgical stapler 10.

Locking member actuator 322 is slidably positioned within axial slot 325formed in upper housing half section 103 a of body portion 103 ofloading unit 100. Actuator 322 includes a proximal abutment member 336,a distal spring guide 327, and a central cam slot 340. An axial slot 341in the housing half section 103 a intersects transverse slot 325 suchthat cam member 328 of locking member 320 is slidably positioned withincam slot 340 of locking member actuator 322. A biasing member or spring342 is positioned about spring guide 327 between a distal surface ofactuator 322 and a wall 341 a defining the distal end of axial slot 341.Spring 342 urges actuator 322 to a first position within axial slot 341.In the first position, abutment member 336 is positioned on an insertiontip 350 of proximal body portion 102 and cam slot 340 is positioned tolocate cam member 328 such that finger 330 of lock member 320 ispositioned within notch 362 of drive assembly 360.

Prior to attachment of loading unit 100 onto endoscopic portion 18 ofsurgical stapler 10, spring 342 urges actuator 322 to the first positionto maintain lock member 320 in its first position as discussed above.When insertion tip 350 of loading unit 100 is linearly inserted into theopen end of endoscopic portion 18 (FIG. 2) of surgical stapler 10, nubs352 of insertion tip 350 move linearly through slots (not shown) formedin the open end of endoscopic portion 18. As nubs 352 pass through theslots, the proximal end of abutment member 336, which is angularlyoffset from nubs 352, abuts a wall of endoscopic portion 18 defining theslots for receiving nubs 352 of proximal body portion 103 of loadingunit 300. As loading unit 100 is moved farther into endoscopic portion18, locking member actuator 322 is moved from its first position to itssecond position. As actuator 322 is moved to its second position, lockmember 320 is cammed from its first position engaged with notch 362 ofdrive assembly 360 to its second position to move finger 330 from notch362. Locking mechanism 310 including locking member 320 and lockingmember actuator 322 prevents advancement of drive assembly 360 ofloading unit 100 prior to loading of loading unit 100 onto endoscopicportion 18.

Locking member actuator 322 includes an articulation lock portion 337disposed thereon. In particular, articulation lock portion 337 extendsin an approximate right angle from abutment member 336. Articulationlock portion 337 is configured to physically prevent the longitudinaltranslation of an articulation member (not shown) of handle assembly 12(FIG. 1A) of surgical stapler 10. That is, even when loading unit 100 isengaged with endoscopic portion 18, articulation lock portion 337 ofloading unit 100 prevents the articulation member from entering loadingunit 100.

During operation of stapler 10, actuation of its movable handle 22through successive strokes causes distal advancement of its drive bar(not shown), such that the drive bar pushes drive assembly 360 throughcartridge 118. (Further details of how actuation of movable handle 22causes distal advancement of the drive bar is explained in U.S. Pat. No.6,953,139 to Milliman et al., the entire contents of which isincorporated by reference herein.) The movement of drive assembly 360moves longitudinally curved actuation sled 136 through cartridge 118. Assled 136 moves through cartridge 118, actuation sled 136 sequentiallyengages pushers 132 to move pushers 132 vertically within stapleretention slots 128 and eject staples 130 into the staple formingdepressions (not shown) of anvil plate 112. Subsequent to the ejectionof staples 130 from retention slots 128 (and into tissue), a dynamicclamping member or knife 306 severs the stapled tissue as knife 306travels through curved slot 126 of cartridge 118.

The present disclosure also relates methods of using the describedsurgical stapler 10 to perform a lower anterior resection. Such a methodincludes providing surgical stapler 10, positioning jaw members adjacenttissue, approximating one jaw member (e.g., cartridge assembly 108) withrespect to the other jaw member (e.g., anvil assembly 106), advancingdrive assembly 360 such that knife 306 and at least a portion of driveassembly 360 move along a curvilinear path to cause staples 130 to beejected into tissue and to cut tissue . In certain embodiments, the jawmembers are approximated, and the interior of the intestinal tissue isthen washed out or otherwise cleansed. The tissue is then cut andstapled. In this way, the interior intestinal tissue is cleansed up tothe location of the jaw members.

While the above description contains many specifics, these specificsshould not be construed as limitations on the scope of the presentdisclosure, but merely as illustrations of various embodiments thereof.Therefore, the above description should not be construed as limiting,but merely as exemplifications of various embodiments. Those skilled inthe art will envision other modifications within the scope and spirit ofthe claims appended hereto.

1. A mounting member for a surgical stapler, comprising: a bodyfabricated from a plastic and defining a longitudinal axis, the bodyincluding: a proximal end portion having a pair of vertical projectionsconfigured to be coupled to a proximal body portion of a loading unit ofa surgical stapler; and a distal end portion including: a pair of wallsextending distally from the proximal end portion; a boss coupled to onewall of the pair of walls and defining a bore therethrough configured tobe rotatably coupled to a cartridge assembly of a loading unit; and astrut extending from the proximal end portion to the boss.